Single lane suburban roundabouts


Single-lane roundabouts: we have a lot of them in our suburbs including at some very busy intersections (Oxford St Bulimba, Agnew St Morningside, Thynne Rd Morningside, Barrack Rd Cannon Hill, Ferguson Rd Seven Hills, Bennetts Rd Norman Park, Wondall Rd Wynnum, etc). For people on bikes, it’s generally accepted as good practice to ‘take the lane’ going into a roundabout so that drivers are more likely to see you, and those behind will not try to squeeze past. But sometimes that just feels uncomfortable – particularly on an uphill approach, or when motor traffic is travelling particularly fast. Roundabouts can feel quite hostile to people walking too, as drivers do not have to give way to pedestrians crossing the street they are turning into.

Unfortunately Queensland did not adopt the recommendation of the 2013 Parliamentary Inquiry into Cycling Issues for lower speed limits at roundabouts, but there has been some recognition that the design of our roundabouts is unfriendly to people on bicycles. There are some great images of roundabout treatments overseas that can be applied when the intersecting roads have separated cycle tracks – but that’s not the scenario at any of our local roundabouts.

grandjunctionsmbikelaneSo how could our roundabouts be improved where we have only on-road bike lanes or no cycling facilities on the roads leading into the roundabout? This illustration from a website talking about roundabouts in Alaska suggests a simple solution that doesn’t take any more room than our existing design:

  1. Narrow the lane widths of the roads entering and exiting the roundabout, at the same time making the approaches more radial (as opposed to our current tangential designs). This will have the effect of slowing traffic, so confident riders can still take the lane and proceed through the roundabout as another vehicle, however
  2. Provide ramps to allow slower or less confident riders to exit the on-road bike lane before the roundabout, and then use the shared path and pedestrian crossings to navigate the intersection before re-joining the on-road lane when they exit.
  3. Set back the pedestrian crossing points one car length from the roundabout so drivers aren’t too busy watching for their gap in traffic to notice pedestrians (and cyclists) waiting to cross.
  4. Provide priority pedestrian crossings (zebra crossings) – preferably raised to make drivers aware that they must give way, and to act as speed cushions.

To see how this might work at one nearby intersection, here are some lines overlaid on an aerial view of the roundabout where Thynne Rd, Pashen St, and Burrai St come together at Morningside:

How the roundabout could be reconfigured to be safer